I. Field of the Invention
The present invention relates generally to apparatus for crushing rock into aggregate and, more particularly, to such apparatus utilizing a uniquely supported movable jaw which assures maximum production of aggregate.
II. Description of the Prior Art
In conventional practice, jaw crushers of the type utilizing a single or a pair of pivoted jaws have long been known. In typical fashion, the jaws are usually mounted at their upper regions on an eccentric with a toggle being provided at the lower region of the jaw. Through the action of the eccentric, the jaw is moved to and from its innermost crushing position. These jaw crushers are very powerful but because of the mass of the structure, and particularly the eccentric drive mechanism, the frequency at which they are capable of operating is relatively low resulting in limited productivity. In jaw crushers of this construction, the moving jaw forces the rock to be crushed both up and down causing severe rubbing action which quickly wears out the jaw plates and wastes power. Maximum motion is at the top, resulting in minimum leverage being applied on the largest rock where maximum leverage is actually needed. As would be expected, bearing pressures are substantial.
A variation of the overhead eccentric type of crusher just described is the Blake type crusher. In this instances, a jaw swings on a fixed axle while a pitman whose upper end follows an eccentric is employed to operate a toggle which, in turn, swings the lower end of the jaw toward an opposed fixed jaw. The swing jaw forces rock upward and causes it to rub against both the fixed and the movable jaw. This rapidly wears out the jaw plates and can consume as much as forty percent of the power imparted to the movable jaw. Being a heavy unbalanced design, this type of crusher must be operated slowly, resulting in a low output and a relatively poor end product.
Typical of a line of improved jaw type crushers is U.S. Pat. No. 3,386,667 to May which discloses a hydraulic actuator for a movable jaw. The movable jaw is pivotally mounted at its upper region with a hydraulic actuating mechanism being connected with the lower region, effective to pivot the jaw about its pivotal mounting. The crusher may be of the type which has a pair of opposed jaws or it may have only a single jaw which is moved toward and away from a fixed jaw. With this mechanism, a high frequency of operation of the crusher jaw is obtained while at the same time great power can be exerted. With this increase in frequency over the earlier conventional designs just discussed, there is an increase in productivity and a better crushed product cubicity. Furthermore, the hydraulic actuating mechanism imparts a higher impact velocity to the crusher jaw and therefore, in turn, to the rock being crushed, thereby more readily fracturing hard materials.
It was with knowledge of the prior art as just described, that the present invention has been conceived and is now reduced to practice. By reason of the present invention, even greater productivity can be achieved while assuring a uniform sought-after end product with minimal wear to the jaw plates and other components of the machine.